backtrace() doesn't exist in non-glibc systems

remove unused size_t size
remove unused void *array[BT_SIZE];

removed CRASHLOG_STDERR_WRITE

fix miniupnpc typo in features.mk

Raise the skin limit

See merge request !1466

OpenGL: Fix linedef type 10 not culling FOFs (Closes #438)

Closes #438

See merge request !1399

Make Dead / NoClipHeight Objects Immune to Death Pits (Resolves #553)

Closes #553

See merge request !2001

Copy Interpolation to Shields and Overlays, Splitscreen Overlays

Closes #997

See merge request !1992

Expose P_IsLocalPlayer to Lua

See merge request !1997

Rewrite M_DrawStaticBox

Closes #1014

See merge request !1990

Always Allow con_hudlines when Using devmode

See merge request !1987

Made filesearch aware of symbolic links

See merge request !1976

Update mobj floorz/ceilingz after a bustable FOF is destroyed

See merge request !1945

Implement perfstats options for LUAh_PreThinkFrame and LUAh_PostThinkFrame

See merge request !1932

Add transparency flag support to drawFill

See merge request !1881

Move player friction reset after movement code for lua qol

See merge request !1824

Fix line.sidenum[i] in Lua

See merge request !2252

made UPnP port mapping enabled by default

See merge request STJr/SRB2!2251

Fix rare but possible menu/console unresponsiveness bug (Resolves #700)

Closes #700

See merge request !1677

Expose a `constants` dictionary to Lua.

See merge request !1646